DOCSLIB.ORG

3Dhgiscience.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
3Dhgiscience.Pdf Heterogeneous Three-Dimensional Electronics by Use of Printed Semiconductor Nanomaterials Jong-Hyun Ahn, et al. Science 314, 1754 (2006); DOI: 10.1126/science.1132394 The following resources related to this article are available online at www.sciencemag.org (this information is current as of December 14, 2006 ): Updated information and services, including high-resolution figures, can be found in the online version of this article at: http://www.sciencemag.org/cgi/content/full/314/5806/1754 Supporting Online Material can be found at: http://www.sciencemag.org/cgi/content/full/314/5806/1754/DC1 This article cites 5 articles, 3 of which can be accessed for free: http://www.sciencemag.org/cgi/content/full/314/5806/1754#otherarticles This article appears in the following subject collections: Physics, Applied http://www.sciencemag.org/cgi/collection/app_physics on December 14, 2006 Information about obtaining reprints of this article or about obtaining permission to reproduce this article in whole or in part can be found at: http://www.sciencemag.org/help/about/permissions.dtl www.sciencemag.org Downloaded from Science (print ISSN 0036-8075; online ISSN 1095-9203) is published weekly, except the last week in December, by the American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. Copyright c 2005 by the American Association for the Advancement of Science; all rights reserved. The title SCIENCE is a registered trademark of AAAS. REPORTS 9. M. Schwarzschild, R. Härm, Astrophys. J. 150, 961 (1967). 21. F. M. Jiménez-Esteban, P. García-Lario, D. Engels, in 9499 (A.M. and P.G.L.) and a MEC JdC grant (J.M.T.R.). 10. R. H. Sanders, Astrophys. J. 150, 971 (1967). Planetary Nebulae as Astronomical Tools, R. Szczerba, This work is based on observations obtained at the 11. M. Busso, R. Gallino, G. J. Wasserburg, Annu. Rev. Astron. G. Stasinska, S. K. Gorny, Eds. (AIP Conference Proceedings, 4.2-m William Herschel Telescope, operated on the Astrophys. 37, 239 (1999). vol. 804, American Institute of Physics, Melville, NY, 2005), island of La Palma by the Isaac Newton Group in the 12. O. Straniero et al., Astrophys. J. 440, L85 (1995). pp. 141–144. Observatorio del Roque de Los Muchachos of the 13.J.W.Truran,I.IbenJr.,Astrophys. J. 216, 797 22. P. Ventura et al., Astrophys. J. 550, L65 (2001). Instituto de Astrofisica de Canarias, and on observations (1977). 23. C. M. O’D. Alexander, Philos. Trans. R. Soc. London Ser. A obtained with the 3.6-m telescope at ESO–La Silla 14. H. Beer, R. L. Macklin, Astrophys. J. 339, 962 (1989). 359, 1973 (2001). Observatory (Chile). 15. C. Abia et al., Astrophys. J. 559, 1117 (2001). 24. E. Zinner et al., Geochim. Cosmochim. Acta 69, 4149 16. D. L. Lambert et al., Astrophys. J. 450, 302 (1995). (2005). 17. J. Tomkin, D. L. Lambert, Astrophys. J. 523, 234 (1999). 25. K. D. McKeegan, A. M. Davis, in Meteorites, Planets, and Supporting Online Material www.sciencemag.org/cgi/content/full/1133706/DC1 18. A. Banerjee, D. Das, V. Natarajan, Europhys. Lett. 65, Comets, A. Davis, Ed., vol. 1 of Treatise on Geochemistry Fig. S1 172 (2004). (Elsevier-Pergamon, Oxford, 2003), pp. 431–460. 19.N.Grevesse,A.J.Sauval,Space Sci. Rev. 85, 161 26. F. A. Podosek et al., Geochim. Cosmochim. Acta 55, 10 August 2006; accepted 19 October 2006 (1998). 1083 (1991). Published online 9 November 2006; 20. P. S. Chen, R. Szczerba, S. Kwok, K. Volk, Astron. 27. Supported by the Spanish Ministerio de Educación y 10.1126/science.1133706 Astrophys. 368, 1006 (2001). Ciencia (MEC) grants AYA 2004-3136 and AYA 2003- Include this information when citing this paper. this method avoids some of the aforementioned problems, the requirements for epitaxy place Heterogeneous Three-Dimensional severe restrictions on the quality and type of materials that can be grown, even when buffer Electronics by Use of Printed layers and other advanced techniques are used (1, 13). Semiconductor Nanomaterials By contrast, nanoscale wires, ribbons, mem- branes, or particles of inorganic materials, or Jong-Hyun Ahn,1,2,3 Hoon-Sik Kim,5 Keon Jae Lee,1,3 Seokwoo Jeon,1,2,3 Seong Jun Kang,1,2,3 carbon-based systems such as single-walled Yugang Sun,1,2,3 Ralph G. Nuzzo,1,2,3,4 John A. Rogers1,2,3,4,5* carbon nanotubes (SWNTs) or graphene sheets (14–17), can be grown and then suspended in We developed a simple approach to combine broad classes of dissimilar materials into solvents or transferred onto substrates in a on December 14, 2006 heterogeneously integrated electronic systems with two- or three-dimensional layouts. The process manner that bypasses the need for epitaxial begins with the synthesis of different semiconductor nanomaterials, such as single-walled carbon growth or wafer bonding. Recent work has nanotubes and single-crystal micro- and nanoscale wires and ribbons of gallium nitride, silicon, shown the integration of isolated crossed nano- and gallium arsenide on separate substrates. Repeated application of an additive, transfer printing wire diodes in 2D layouts formed by solution process that uses soft stamps with these substrates as donors, followed by device and interconnect casting (18). Our results show how dissimilar formation, yields high-performance heterogeneously integrated electronics that incorporate any single-crystal inorganic semiconductors (such combination of semiconductor nanomaterials on rigid or flexible device substrates. This versatile as micro- and nanoscale wires and ribbons of methodology can produce a wide range of unusual electronic systems that would be impossible to GaN, Si, and GaAs) can be combined with one achieve with other techniques. another and also with other classes of nano- www.sciencemag.org materials (such as SWNTs) with the use of a any existing and emerging electronic chip-scale bonding (1, 2, 6, 8–10) and epitaxial scalable and deterministic printing method to devices benefit from the heteroge- growth (3, 11, 12) represent the two most widely yield complex, heterogeneously integrated Mneous integration of dissimilar classes used methods for achieving these types of electronic systems in 2D or 3D layouts. The of semiconductors into single systems, in either integrated systems. capabilities of this process are demonstrated by two-dimensional (2D) or 3D layouts (1, 2). Ex- The bonding processes use fusion processes ultrathin multilayer stacks of high-performance amples include multifunctional radio-frequency (8, 9) or layers of adhesives (6, 10) to combine metal oxide semiconductor field-effect transis- communication devices, infrared imaging cam- integrated circuits, photodiodes, or sensors tors (MOSFETs), high electron mobility tran- Downloaded from eras, addressable sensor arrays, and hybrid sili- formed separately on different semiconductor sistors (HEMTs), thin-film transistors (TFTs), con complementary metal oxide semiconductor wafers. This approach works well in many photodiodes, and other components that are (CMOS) circuits and nanowire devices (3–7). cases, but it has important drawbacks (1, 9), integrated into device arrays, logic gates, and In some representative systems, compound semi- including (i) limited ability to scale to large actively addressable photodetectors on rigid conductors or other materials provide high-speed areas (i.e., larger than the wafers) or to more inorganic and flexible plastic substrates. operation, efficient photodetection, or sensing than a few layers in the third (i.e., stacking) Figure 1 illustrates representative steps for capabilities; the silicon CMOS provides digital dimension; (ii) incompatibility with unusual producing these types of systems. The process readout and signal processing in circuits that of- materials (such as nanostructured materials) begins with the synthesis of the semiconductor ten involve stacked 3D configurations. Wafer- or and/or low-temperature materials and substrates; nanomaterials, each on their own source sub- (iii) challenging fabrication and alignment for strate. The devices shown in Fig. 1 allow micro- 1Department of Materials Science and Engineering, Uni- the through-wafer electrical interconnects; (iv) and nanoscale wires and ribbons of single- versity of Illinois, Urbana-Champaign, IL 61801, USA. demanding requirements for planar bonding crystalline GaN, GaAs, and Si that were formed 2Beckman Institute for Advanced Science and Technology, University of Illinois, Urbana-Champaign, IL 61801, USA. surfaces; and (v) bowing and cracking that can with the use of wafer-based source materials 3Frederick Seitz Materials Research Laboratory, University occur from mechanical strains generated by and lithographic etching procedures (19–23)to of Illinois, Urbana-Champaign, IL 61801, USA. 4Department differential thermal expansion and contraction be integrated with each other or with networks of Chemistry, University of Illinois, Urbana-Champaign, IL of disparate materials. Epitaxial growth provides of SWNTs that were grown by chemical vapor 61801, USA. 5Department of Electrical and Computer En- gineering, University of Illinois, Urbana-Champaign, IL 61801, a different approach, which uses molecular deposition (16, 23). Scanning electron micro- USA. beam epitaxy or other means to form thin layers graphs at the top of Fig. 1 show these *To whom correspondence should be addressed. E-mail: of semiconductor materials directly on the semiconductor nanomaterials after their removal [email protected] surfaces of wafers of other materials. Although from the source substrates. For circuit fabrica- 1754 15 DECEMBER 2006 VOL 314 SCIENCE www.sciencemag.org REPORTS tion, these elements remain in the configurations Second, the method is applicable to broad optical micrograph of an edge of the system; the defined on the wafers during the fabrication or classes of semiconductor nanomaterials, includ- layout of the system was designed to reveal growth stage: aligned arrays in the case of the GaN, ing emerging materials such as SWNTs. Third, separately the parts of the substrate that sup- GaAs, and Si materials, and submonolayer random the soft stamps enable nondestructive contacts port one, two, and three layers of MOSFETs.
Load more

Recommended publications
  • View Publication
    Spin-orbit physics of j=1/2 Mott insulators on the triangular lattice Michael Becker,1 Maria Hermanns,1 Bela Bauer,2 Markus Garst,1 and Simon Trebst1 1Institute for Theoretical Physics, Cologne University, Zulpicher¨ Straße 77, 50937 Cologne, Germany 2Station Q, Microsoft Research, Santa Barbara, CA 93106-6105, USA (Dated: April 16, 2015) The physics of spin-orbital entanglement in effective j = 1=2 Mott insulators, which have been experi- mentally observed for various 5d transition metal oxides, has sparked an interest in Heisenberg-Kitaev (HK) models thought to capture their essential microscopic interactions. Here we argue that the recently synthesized Ba3IrTi2O9 is a prime candidate for a microscopic realization of the triangular HK model – a conceptually interesting model for its interplay of geometric and exchange frustration. We establish that an infinitesimal Ki- taev exchange destabilizes the 120◦ order of the quantum Heisenberg model. This results in the formation of an extended Z2-vortex crystal phase in the parameter regime most likely relevant to the real material, which can be experimentally identified with spherical neutron polarimetry. Moreover, using a combination of analytical and numerical techniques we map out the entire phase diagram of the model, which further includes various ordered phases as well as an extended nematic phase around the antiferromagnetic Kitaev point. I. INTRODUCTION yond the hexagonal lattice, triggered mainly by the synthe- sis of novel Iridate compounds, which includes e.g. the sis- 16 17 ter compounds β-Li2IrO3 and γ-Li2IrO3 that form three- The physics of transition metal oxides with partially filled dimensional Ir lattice structures.
    [Show full text]
  • Quantum Spin Hall Effect in Topological Insulators
    Racah Institute of Physics Hebrew University of Jerusalem Quantum spin Hall effect in topological insulators Edouard Sonin 7KH&DSUL6SULQJ6FKRRORQ7UDQVSRUWLQ1DQRljUXFWXUHV&DSUL$SULO Content Spin Hall effect Topological Insulator Quantum spin Hall effect: (i) Was it really observed? (ii) If not, how and whether could it be observed? Spin Hall effect ! ! !"#$%&%' ( )*+*, -./0.1 23+456 -.///1 Spin balance @S h + J = G Spin: SpinS = balance( y ) @t ri i 2 h Spin current: @S h Ji = ( y{ vi + vi } ) Spin: S = ( y ) 4 + iJi = G 2 Spin@t balancer Spin balance ~v is the group-velocity operator h Spin current: J = ( y{ vSonin+ v" } ) @S i h i i @S Adv.4 Phys. 59, 181 (2010)h " + iJ = G Rashba model: Spin: S = Spin:( y S ) = ( y ) i + iJi = G 2 @t r h @t r ~v is the group-velocity operator 2 ~v = ( i~ +h [^z ~]) Spin current: h mSpin Jcurrent:ir= ( y{ Jvi =+ vi( }y {) Rashbav + v model:} ) 4 i 4 i i i h2 h Torque: G~ v =is the group-velocity y{[~ operator[^z~v = ~ ]]( i}~ + [^{z[[~ ~])z^] ~] y} 2m ~v is the group-velocity rm roperator r n o Rashba model: 2 Rashbai h model: ~ ~ 2 h Torque: G = 2 y{[~ [^z ]] } {[[ z^] ~] y} ih ~ h h 2m r r Ji = ~v(= y ( i +~v =[^iz y(~ ]) i~) + [^z ( ~y])n{ [~ z^]i +[~ z^]i } ) o 4m m r r r m r 4m 2 i h i ihh22 h2 G = y{[~ [^z ~ ]] } {[[~ z^] ~] y} Torque: Torque: G Ji== ( yy { [~i [^z i ~ ]]y }) { [[(~ y{z^] [~~] z^ ]iy+[} ~ z^]i } ) 2m 24mm r r r rr 4m r n n o o ih2 2 h2 2 ih h Ji = ( Jy = i ( i yy ) (y y{ ) [~ z^](i +[y{~ [~z^]iz^ ]} +[) ~ z^] } ) 4m i r 4mr ri r4mi 4m i i Are spin currents
    [Show full text]
  • Quantum Spin Hall Effect and Topological Insulators for Light
    Quantum spin Hall effect and topological insulators for light Konstantin Y. Bliokh1,2 and Franco Nori1,3 1Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198, Japan 2Nonlinear Physics Centre, RSPhysE, The Australian National University, ACT 0200, Australia 3Physics Department, University of Michigan, Ann Arbor, Michigan 48109-1040, USA We show that free-space light has intrinsic quantum spin-Hall effect (QSHE) properties. These are characterized by a non-zero topological spin Chern number, and manifest themselves as evanescent modes of Maxwell equations. The recently discovered transverse spin of evanescent modes demonstrates spin-momentum locking stemming from the intrinsic spin-orbit coupling in Maxwell equations. As a result, any interface between free space and a medium supporting surface modes exhibits QSHE of light with opposite transverse spins propagating in opposite directions. In particular, we find that usual isotropic metals with surface plasmon- polariton modes represent natural 3D topological insulators for light. Several recent experiments have demonstrated transverse spin-momentum locking and spin- controlled unidirectional propagation of light at various interfaces with evanescent waves. Our results show that all these experiments can be interpreted as observations of the QSHE of light. 1. Introduction Solid-state physics exhibits a family of Hall effects with remarkable physical properties. The usual Hall effect (HE) and quantum Hall effect (QHE) appear in the presence of an external magnetic field, which breaks the time-reversal ( T ) symmetry of the system. The HE represents charge-dependent deflection of electrons orthogonal to the magnetic field, whereas the QHE [1] offers distinct topological electron states, with unidirectional edge modes (charge-momentum locking), characterized by the topological Chern number [2].
    [Show full text]
  • Room Temperature Electrically Pumped Topological Insulator Lasers
    ARTICLE https://doi.org/10.1038/s41467-021-23718-4 OPEN Room temperature electrically pumped topological insulator lasers Jae-Hyuck Choi1, William E. Hayenga1,2, Yuzhou G. N. Liu 1, Midya Parto 2, Babak Bahari1, ✉ Demetrios N. Christodoulides 2 & Mercedeh Khajavikhan 1,2 Topological insulator lasers (TILs) are a recently introduced family of lasing arrays in which phase locking is achieved through synthetic gauge fields. These single frequency light source 1234567890():,; arrays operate in the spatially extended edge modes of topologically non-trivial optical lat- tices. Because of the inherent robustness of topological modes against perturbations and defects, such topological insulator lasers tend to demonstrate higher slope efficiencies as compared to their topologically trivial counterparts. So far, magnetic and non-magnetic optically pumped topological laser arrays as well as electrically pumped TILs that are oper- ating at cryogenic temperatures have been demonstrated. Here we present the first room temperature and electrically pumped topological insulator laser. This laser array, using a structure that mimics the quantum spin Hall effect for photons, generates light at telecom wavelengths and exhibits single frequency emission. Our work is expected to lead to further developments in laser science and technology, while opening up new possibilities in topological photonics. 1 Ming Hsieh Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, USA. 2 CREOL, The College of Optics ✉ and Photonics,
    [Show full text]
  • The Quantum Spin Hall Effect and Topological Insulators Xiao-Liang Qi, and Shou-Cheng Zhang
    The quantum spin Hall effect and topological insulators Xiao-Liang Qi, and Shou-Cheng Zhang Citation: Physics Today 63, 1, 33 (2010); doi: 10.1063/1.3293411 View online: https://doi.org/10.1063/1.3293411 View Table of Contents: http://physicstoday.scitation.org/toc/pto/63/1 Published by the American Institute of Physics Articles you may be interested in Foundational theories in topological physics garner Nobel Prize Physics Today 69, 14 (2016); 10.1063/PT.3.3381 Two-dimensional van der Waals materials Physics Today 69, 38 (2016); 10.1063/PT.3.3297 Topological phases and quasiparticle braiding Physics Today 65, 38 (2012); 10.1063/PT.3.1641 Surprises from the spin Hall effect Physics Today 70, 38 (2017); 10.1063/PT.3.3625 Topological quantum computation Physics Today 59, 32 (2006); 10.1063/1.2337825 Fifty years of Anderson localization Physics Today 62, 24 (2009); 10.1063/1.3206091 The quantum spin Hall effect and feature topological insulators Xiao-Liang Qi and Shou-Cheng Zhang In topological insulators, spin–orbit coupling and time-reversal symmetry combine to form a novel state of matter predicted to have exotic physical properties. Xiao-Liang Qi is a research associate at the Stanford Institute for Materials and Energy Science and Shou-Cheng Zhang is a professor of physics at Stanford University in Stanford, California. In the quantum world, atoms and their electrons can crystals.6–8 QSH systems are insulating in the bulk—they have form many different states of matter, such as crystalline solids, an energy gap separating the valence and conduction bands— magnets, and superconductors.
    [Show full text]
  • Download Ultrasonic Spectroscopy Applications in Condensed Matter
    ULTRASONIC SPECTROSCOPY APPLICATIONS IN CONDENSED MATTER PHYSICS AND MATERIALS SCIENCE 1ST EDITION DOWNLOAD FREE BOOK Robert G Leisure | --- | --- | --- | 9781107154131 | --- | --- Condensed matter physics Built by scientists, for scientists. My research interests are motivated by this remarkable observation. One example is the incorporation of multiple functionalities such as superconductivity, magnetism, and ferroelectricity into a single material platform in search of multifunctionality. Cold atoms in optical lattices are used as quantum simulatorsthat is, they act as controllable systems that can model behavior of more complicated systems, such as frustrated magnets. One major project involves studies of ultrathin dielectrics silicon oxynitrides and metaloxides for nanoelectronic devices. Optical absorption and fluorescence spectroscopy measurements have become an important tool for structure-based characterization and DNA- assisted manipulation of carbon nanotubes. Other vigorous areas of research include such phenomena as metal-insulator transition, two- dimensional electron systems, magnetism, and quantum fluids and solids. In these systems, density currents propagating in chiral edge states are protected from scattering with disorder, which is a clear advantage for exciton based optical circuits. Branch of physics. Introduction to Many Body Physics. We can also create novel multiferroic, superconducting or ferroelectric materials by means of atomic-scale crystal-symmetry engineering. The methods are suitable to study defects, diffusion,
    [Show full text]
  • Imaging Currents in Hgte Quantum Wells in the Quantum Spin Hall Regime Katja C
    Imaging currents in HgTe quantum wells in the quantum spin Hall regime Katja C. Nowack2,3*, Eric M. Spanton1,3, Matthias Baenninger1,3, Markus König1,3, John R. Kirtley2, Beena Kalisky2,4, C. Ames5, Philipp Leubner5, Christoph Brüne5, Hartmut Buhmann5, Laurens W. Molenkamp5, David Goldhaber-Gordon1,3, Kathryn A. Moler1,2,3 1Department of Physics, Stanford University, Stanford, California 94305, USA 2Department of Applied Physics, Stanford University, Stanford, California 94305, USA 3Stanford Institute for Materials and Energy Science, Stanford University, Stanford, California 94305, USA 4Department of Physics, Nano-magnetism Research Center, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel. 5Physikalisches Institut (EP3), Universität Würzburg, Am Hubland, D-97074, Würzburg, Germany *To whom correspondence should be addressed. Email: [email protected] The quantum spin Hall (QSH) state is a genuinely new state of matter characterized by a non-trivial topology of its band structure1-5. Its key feature is conducting edge channels whose spin polarization has potential for spintronic and quantum information applications. The QSH state was predicted6 and experimentally demonstrated7 to exist in HgTe quantum wells. The existence of the edge channels has been inferred from the fact that local and non- local conductance values in sufficiently small devices are close to the quantized values expected for ideal edge channels7,8 and from signatures of the spin polarization9. The robustness of the edge channels in larger devices and the interplay between the edge channels and a conducting bulk are relatively unexplored experimentally, and are difficult to assess via transport measurements. Here we image the current in large Hallbars made from HgTe quantum wells by probing the magnetic field generated by the current using a scanning superconducting quantum interference device (SQUID)10.
    [Show full text]
  • What Is the Quantum Spin Hall Effect? What Is the Quantum Spin Hall Effect?
    What is the quantum spin Hall effect? What is the quantum spin Hall effect? Fir! paper on "in Hal e$ect: D’yakonov and Perel ’, 1971 What is the quantum spin Hall effect? Recall the quantum Hall effect... Recall the quantum Hall effect... impurity scattering broadening of Landau levels into bands of localized states bulk insulator Recall the quantum Hall effect... What carries the current?! Recall the quantum Hall effect... What carries the current?! “skipping currents”! Recall the quantum Hall effect... 1 “skipping currents” conducting edge states quantization Halperin (1982) e2 No channel for backscattering ballistic transport = iv :R† (x)∂ R (x)::L† (x)∂ L (x): G = ν Hτ − F τ x τ τ x τ h 2ik0 (x+a/2) $ % 2∆R cos(Qx) e− F R† (x)L (x)+H.c.(6), − τ τ A QH state is stable against local perturbations $ % M 100 meV c ≈ τ = D. Grundler, Phys. Rev. Lett. 84, 6074 (2000) ± W. H¨ausler, L. Kecke, and A. H. MacDonald, Phys. Rev. B 65, 085104 (2002) q0 11 !α0 2 10− eV m " × y H = i (γ + γ cos (Qna)) c† σ c H.c. Λ 0.5 eV R − 0 1 n,µ µν n+1,ν − " n,µ,ν v 1 106 m/s & ' ( F " × Kc + Ks 1.8 " 1 γj = αja− (j = 0, 1) HR ϕc (ϕ+ + ϕ )/√2 (7) ≡ − H = dx [ + ] Hc Hs ϕs (ϕ+ ϕ )/√2 (8) ! ≡ − − v m = i [(∂ ϕ )2 +(∂ ϑ )2] i cos( 2πK ϕ ), (1) Hi 2 x i x i − πa i i int = g1 :Rτ† Lτ L† τ R τ : + g˜2τ :R+† R+Lτ† Lτ : " H − − − g4τ + (:R+† R+Rτ† Rτ : + R L) (9) ∆R = γ1 sin(q0a) 2 ↔ with vi and Ki functions of g1τ , g˜2τ and g4τ g˜ g δ g (10) 2τ ≡ 2τ − τ+ 1τ Λ bandwidth (2) ∼ with vi and K functions of g1τ , g2τ , g3τ (11) ϕc (ϕ+ + ϕ )/√2 (3) ≡ − (+, ) ( , ) in ”g-ology” notation (12) − ↔ ) ⊥ ϕs (ϕ+ ϕ )/√2 (4) ≡ − − ∂tϕτ = vF ∂xϑτ Rτ† and Lτ† create excitations at the Fermi points of the right- and left-moving branches with spin projection τ R (x) = η exp i√π[ϕ (x) + ϑ (x)] /√2πa (5) τ τ τ τ $ % L+ L (x) = η¯ exp i√π[ϕ (x) ϑ (x)] /√2πa τ τ − τ − τ $ % 2 2 vF = 2a t + γ0 and ∆R = γ1 sin(q0a) ητ , η¯τ Klein factors # Can a system be stable against local perturbations without breaking time-reversal invariance? Consider a Gedanken experiment..
    [Show full text]
  • Extreme Mechanics Letters Programmable Elastic Valley Hall
    Extreme Mechanics Letters 28 (2019) 76–80 Contents lists available at ScienceDirect Extreme Mechanics Letters journal homepage: www.elsevier.com/locate/eml Programmable elastic valley Hall insulator with tunable interface propagation routes ∗ Quan Zhang, Yi Chen, Kai Zhang, Gengkai Hu Key Laboratory of Dynamics and Control of Flight Vehicle, Ministry of Education, School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, China article info a b s t r a c t Article history: A challenge in the area of topologically protected edge waves in elastic media is how to tune the Received 28 December 2018 topological interface propagation route as needed. This paper proposes a tunable elastic valley Hall Received in revised form 25 January 2019 insulator, whose unit cell consists of two cavities and magnetic fluid with the same volume as the Accepted 12 March 2019 cavity. Interface route with arbitrary shape for propagating topologically protected edge waves can Available online 15 March 2019 be achieved by controlling the distribution of magnetic fluid in each unit cell through a designed Keywords: programmable magnet lifting array. As demonstrated through numerical simulations and experimental Elastic topological insulator testing, the flexural wave is confined to propagate along the topological interface routes of different Programmable interface propagation route configurations. Finally, it is indicated that the proposed valley Hall insulator can be applied to achieve Topologically protected edges wave desired localized elastic energy which is robust to defects, sharp corners and so on. Wave guiding ' 2019 Elsevier Ltd. All rights reserved. 1. Introduction needed to break time-reversal symmetry (TRS). In acoustic/elastic system, the mostly common used method to break TRS is by During the past decades, manipulating wave propagation in exploiting rotating inclusions, such as spinning rotors [12,14] or periodic materials has attracted significant interest.
    [Show full text]
  • Photonic Analogue of Quantum Spin Hall Effect Cheng He1*, Xiao
    Photonic analogue of quantum spin Hall effect Cheng He1*, Xiao-Chen Sun1*, Xiao-ping Liu1,Ming-Hui Lu1†, YulinChen2, Liang Feng3 and Yan-Feng Chen1† 1National Laboratory of Solid State Microstructures& Department of Materials Science and Engineering, Nanjing University, Nanjing 210093, China 2Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK 3Department of Electrical Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA *These authors contributed equally to this work. †Correspondence and request for materials should be addressed to M. H. Lu ([email protected]) and Y. F. Chen ([email protected]). Symmetry-protected photonic topological insulator exhibiting robust pseudo-spin-dependent transportation1-5, analogous to quantum spin Hall (QSH) phases6,7 and topological insulators8,9, are of great importance in fundamental physics. Such transportation robustness is protected by time-reversal symmetry. Since electrons (fermion) and photons (boson) obey different statistics rules and associate with different time-reversal operators (i.e., Tf and Tb, respectively), whether photonic counterpart of Kramers degeneracy is topologically protected by bosonic Tb remains unidentified. Here, we construct the degenerate gapless edge states of two photonic pseudo-spins (left/right circular polarizations) 1 in the band gap of a two-dimensional photonic crystal with strong magneto-electric coupling. We further demonstrated that the topological edge states are in fact protected by Tf rather than commonly believed Tb and their pseudo-spin dependent transportation is robust against Tf invariant impurities, discovering for the first time the topological nature of photons. Our results will pave a way towards novel photonic topological insulators and revolutionize our understandings in topological physics of fundamental particles.
    [Show full text]
  • UCLA Electronic Theses and Dissertations
    UCLA UCLA Electronic Theses and Dissertations Title A Study of d-Density Wave States in Strongly Correlated Electron Systems Permalink https://escholarship.org/uc/item/5vd202j4 Author Hsu, Chen-Hsuan Publication Date 2014 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA Los Angeles A Study of d-Density Wave States in Strongly Correlated Electron Systems A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Physics by Chen-Hsuan Hsu 2014 ⃝c Copyright by Chen-Hsuan Hsu 2014 ABSTRACT OF THE DISSERTATION A Study of d-Density Wave States in Strongly Correlated Electron Systems by Chen-Hsuan Hsu Doctor of Philosophy in Physics University of California, Los Angeles, 2014 Professor Sudip Chakravarty, Chair Particle-hole condensates in the angular momentum ` = 2 channel, known as d-density wave or- ders, have been suggested to be realized in strongly correlated electron systems. In this dissertation, we study singlet and triplet d-density wave orders with a form factor of dx2−y2 as well as a novel topological mixed singlet-triplet d-density wave with a form factor of (iσdx2−y2 +dxy), and discuss the connections of these states to high-temperature superconductors and heavy-fermion materials. In Chapter 2, we discuss the spin susceptibility of the singlet d-density wave, triplet d-density wave, and spin density wave orders with hopping anisotropies. From the numerical calculation, we find nearly vertical dispersion relations for spin excitations with anisotropic incommensurability at low energies in agreement with the inelastic neutron scattering experiments in the pseudogap state of the high-temperature superconductor YBa2Cu3O6:6.
    [Show full text]
  • Quantum Spin Hall Effect in Two-Dimensional Transition Metal Dichalcogenides Xiaofeng Qian Et Al
    RESEARCH | REPORTS magnitude too slow to produce v-weakening, 3. S. Siman-Tov, E. Aharonov, A. Sagy, S. Emmanuel, Geology 41, 22. J.-P. Gratier, D. K. Dysthe, F. Renard, Adv. Geophys. 54,47–179 except perhaps at temperatures of 500° to 700°C 703–706 (2013). (2013). 4. S. A. F. Smith et al., Geology 41,63–66 (2013). 23. J. R. Farver, R. A. Yund, Contrib. Mineral. Petrol. 123,77–91 reached in experiments at coseismic slip veloc- – 4 5 14 19 5. M. Fondriest et al., Geology 41, 1175 1178 (2013). (1996). ities ( , , , ). 6. J. D. Kirkpatrick, C. D. Rowe, J. C. White, E. E. Brodsky, Geology 24. N. R. Tao et al., Acta Mater. 50, 4603–4616 (2002). The internal polycrystalline substructure of 41, 1015–1018 (2013). 25. L. A. Kennedy, J. C. White, Geology 29, 1027–1030 (2001). the nanospherules and nanofibers that we ob- 7. J. P. Evans, M. R. Prante, S. U. Janecke, A. K. Ault, D. L. Newell, 26. R. L. Penn, J. F. Banfield, Science 281, 969–971 (1998). Geology 42, 623–626 (2014). 27. H. Zhang, J. F. Banfield, CrystEngComm 16, 1568–1578 served bears a striking similarity to microstruc- – 24 8. C. H. Scholz, Nature 391,37 42 (1998). (2014). tures found in shocked ductile metals ( ). As 9. B. A. Verberne, C. He, C. J. Spiers, Bull. Seismol. Soc. Am. 100, 28. N. Gehrke, H. Cölfen, N. Pinna, M. Antonietti, N. Nassif, in metals, the well-known ductility of calcite 2767–2790 (2010). Cryst. Growth Des. 5, 1317–1319 (2005).
    [Show full text]